This study will contribute to a body of scientific nursing knowledge that pertains to health promotion and disease prevention. It seeks to identify the multifaceted determinants of six pregnancy-related health behaviors through the application of a theoretically derived general model of health behavior. This causal model is an extension and revision of the Health Belief Model and incorporates the social and structural contexts in which decisions to engage in health behaviors are made. Further, this study seeks to isolate those factors that may be influenced by nursing and to demonstrate the practical utility of a theoretically general model for guiding nursing interventions to promote and to facilitate positive health behaviors. The health behavior of pregnant women was selected for study because of an extensive literature linking both formal health services and personal health practices to the health of pregnant women and their infants. By understanding what helps pregnant women act in healthful ways, nurses not only may improve the mother's and infant's health, but also may have a broader impact because of mothers' influence of the health behavior and practices of their families. The proposed research is divided into three major components. The first tests the hypothesized model's descriptive and predictive power for each of the six behaviors using a multiple indicators, causal modeling approach. The second focuses on the role of gestational factors and on questions involving the stability of beliefs and practices during pregnancy through extensive analyses of repeated meeasures taken on a subsample of participants early and late in their pregnancies. The third explores the role of clinical indicators that signal potential sub-optimal outcomes of pregnancy. The data for this project currently are in several stages of availability. First are the quantified data from self-administered questionnaires and subsequent telephone interviews with 529 pregnant women obtained through several private obstetrical practices and three large health care facilities. Second are the repeated measures and open-ended items that require coding. Third are health record data will be obtained for this project. Findings from this study will increase our understanding of why people in general, and pregnant women specifically, do not adopt healthy behaviors and thus, will provide a basis for designing more effective interventions.